1. Field of the Invention
The present invention is related to an apparatus for retaining a boot on a glide board especially adapted to snowboarding, the boot comprising an upper that is affixed to a sole adapted to cooperate with the board.
2. Description of Background Information
To date, the above-mentioned type of equipment could broadly be divided into two categories:
equipment that uses rigid boots attached to the board by a system of front and rear stirrups, and whose latching control is located on the rear stirrup which can be activated either manually or automatically; and PA1 equipment that uses flexible boots that are inserted into a shell fixed to the board, such shell comprising a certain number of straps adapted to affix the boot and the shell.
The disadvantage of rigid boots lies mainly in the fact that they do not allow a certain slack that is essential to the sport of snowboarding (lateral rigidity, front bending, asymmetrical behavior), and the comfort factor is also very arbitrary due to their design and the materials used.
In addition, the walking function is not efficient, whereas this is a function that is especially necessary and useful to a snowboarder.
Another disadvantage lies in the fact that the very substantial length of the boot, which is caused by the front and rear projections of the sole that are necessary for gripping the stirrups, results in the ends of the sole of the boot spilling over with respect to the snowboard.
As regards the boots of the second category, the disadvantages lie in the fact that putting on the boot and adjusting the strips is a long and painstaking process, the complementary arrangement of the flexible boot with the rigid shells is unsatisfactory, the shells present an inordinately cumbersome volume on the board, and comfort is inversely proportionate to the good retention of the foot.
In fact, the main advantage of flexible boots lies in the fact that they are essentially comfortable when not being used for snowboarding.
It was on the basis of these observations that the U.S. Pat. No. 5,299,823 described a solution wherein a rigid insert is arranged in the sole, more or less extending between the calcaneum and the metatarsal joint. The disadvantage of such an insert lies in the fact that it stiffens the sole of the boot to an unacceptable degree, whereas such boot claimed to be flexible for the reasons cited hereinabove.
As such, walking with these boots is an uncomfortable as it is with rigid boots.
In regards to the binding itself, the patents FR 2,654,591 and DE 4,311,630 describe the use of latching fingers that come out laterally from the sole and that act both as support and retention members. They use a releasable gripping system originating from the gliding device, and this makes the system both complicated and expensive. One disadvantage linked to these devices lies in the fact that since the sole of the boot functions as the support element on the board, the predetermined distance between the latching finger and the support zone can be disturbed due to wear and tear, or by a wedge of snow that could form under the sole. It is obvious that is such cases it would become impossible to guarantee the fitting of the fingers into the attachment element originating from the board. Further, since the retractable finger functions both as the support and retention elements, it becomes difficult for it to slide freely and correctly into its housing under certain circumstances of use, and in such a case, it would become necessary to oversize the strength of the return springs. In addition, the substantial amounts of energy generated just prior to jumps, for example, will rapidly deteriorate the finger and its housing.